Polymers can be prepared from monomers and/or oligomers in various ways. For example, for the preparation of polymer beads, it is possible to prepare them by a so-called droplet polymerization. In general, for droplet polymerization, liquid monomer is sprayed into a gas phase, which forms individual droplets. The monomer reacts within the droplets to give the polymer and individual polymer beads form. However, the disadvantage of this process is that the falling time of the droplets in the gas phase permits only rapid reactions. These are, for example, the polymerization of acrylic acid to superabsorbance.
In addition to the spraying of liquid monomer, it is also possible to dropletize the liquid monomers in a liquid immiscible therewith. This is known, for example, for the preparation of polymethacrylate from DE-A 30 09 812, or for the preparation of styrene/divinylbenzene copolymers from EP-A 0 173 518. The liquid monomer is in each case dropletized directly within the liquid. However, the disadvantage of the droplet generation in the continuous liquid phase is that it is restricted to large droplets and control of the droplet size is possible only to a reduced degree. A further disadvantage of droplet generation in the continuous phase is that there is a risk of blockage of the nozzle at relatively high temperatures.